COLUMBIA  LIBRARIES  OFFSITE 

HEALTH  SCIENCES  STANDARD 


HX64101231 
QP101  .Ed9  Compensatoiy  ptienome 

^ijmrETifsaTORY^  PHENOMENA    IN    THE    DISTRIBU- 
TION OF  THE  BLOOD  DURING  STIMULATION 
OF  THE  SPLANCHNIC  NERVE 


RECAP 


BT 

D.  J.  EDWARDS 


Department  of  Physiology,  Columbia  University,  New  York  City 


Submitted  in  partial  fulfilment  of  the  requirements  for  the  Degree  of  Doctor 
of  Philosophy,  in  the  faculty  of  Pure  Science,  Colmnbia  University. 


Repbinted  prom 
The  American  Jotibnal  of  Physiologt,  Vol.  XXXV,  No.  1,  AuotrsT,  1914 


4j>jo. 


Reprinted  from  The  American  Journal  of  Physiology,  Vo!.  XXXV,  No.  1 

August,  V.)U 


COMPENSATORY    PHENOMENA    IN    THE    DISTRIBU- 
TION OF  THE  BLOOD  DURING  STIMULATION 
OF  THE  SPLANCHNIC  NERVE 

D.  J.  EDWARDS 
From  the  Department  of  Physiology,  Columbia  University,  New  York  City 

ReoeivGcl  for  publication,  May  18,   1914 

A  study  of  the  transfer  of  the  blood  from  the  arterial  to  the 
venous  side,  during  periods  of  vasoconstriction  affecting  the 
splanchnic  area,  requires  the  special  consideration  of  two  fac- 
tors; namely,  the  quantity  of  blood  that  flows  through  the  portal 
circuit,  and  the  quantity  of  blood  that  traverses  other  divisions 
of  the  circulatory  system. 

The  blood  flow  in  the  portal  vein  of  the  dog  has  been  care- 
fully studied  by  Burton-Opit^,'  measurements  having  been  made 
upon  the  flow  in  the  main  trunk  as  well  as  in  the  tributaries. 
It  has  been  shown  that  vasoconstriction  in  the  abdominal  vis- 
cera causes  a  marked  diminution  in  the  portal  flow.  The  amount 
of  decrease  during  a  period  of  about  20  seconds  of  moderate 
stimulation  of  one  splanchnic  nerve  was  as  much  as  one-fourth 
of  the  quantity  normally  flowing  through  this  vein.  In  work 
upon  the  magnitude  of  the  portal  flow  it  is  stated  "that  a  dog 
having  an  average  body  weight  of  14.3  kgm.  possesses  a  portal 
flow  of  268.2  cc.  per  minute."  If  we  assume  that  the  total 
quantity  of  blood  is  one-thirteenth  of  the  body  Aveight,  it  is 
obvious  that  about  one-fourth  of  the  entire  blood-supply  nor- 
mally passes  through  the  portal  circuit.  This  would  mean  that 
about  one-sixteenth  of  the  blood  of  the  animal,  or  approximately 

'  Burton-Opitz :  Archiv  fiir  die  gesammte  Pliysiologie,  cxxiii,  p.  553,  1908; 
cxxiv,  p.  495,  1908;  oxxix,  p.  189,  1909;  cxxxv,  p.  205,  1910;  and  Quarterly  Journ. 
Physiol.,  1911,  iv,  p.  113. 

15 


16  D.   J.   EDWARDS 

68  cc.  per  minute,  must  find  its  way  into  the  venous  channels 
during  splanchnic  vasoconstriction  through  some  other  course, 
because  the  accumulation  of  this  quantity  of  blood  on  the  arte- 
rial side  would  soon  produce  a  greatly  diminished  venous  return 
to  the  heart  and  consequently  a  diminished  ventricular  output. 

The  large  vascular  area  over  which  the  splanchnic  nerve  exer- 
cises a  powerful  vasomotor  influence,  has  been  regarded  as  occu- 
pying a  reciprocal  relation  to  other  parts  of  the  body.  Thus 
Dastre  and  Morat^  state  that  a  vasoconstriction  in  the  abdomi- 
nal portal  vessels  is  accompanied  by  a  dilatation  of  the  cutane- 
ous vessels,  and  they  postulate  that  a  vasoconstriction  of  the 
cutaneous  vessels  denotes  a  dilatation  of  the  splanchnic  area.  A 
similar  view  has  been  expressed  by  Bayliss  and  Bradford'  who 
state  that  there  is  an  antagonism  of  a  physiological  character 
existing  between  the  vessels  of  the  limb  and  those  of  the  splanch- 
nic area — the  latter  exercising  the  predominant  influence,  v. 
Anrep*  similarly  describes  the  splanchnic  nerve  as  the  regulator 
of  the  blood-supply  of  the  body. 

By  means  of  the  plethysmographic  method  it  has  been  demon- 
strated that  the  volume  of  the  intestine,^  kidney, •*  and  spleen," 
is  greatly  diminished  during  stimulation  of  the  splanchnic  nerve, 
and  a  similar  phenomenon  has  been  shown  with  the  hind  limbs.* 
These  observations  are  of  interest  in  this  connection  because  of 
the  bearing  they  have  upon  the  use  of  the  changes  in  the  volume 
of  an  organ  as  an  index  of  the  quantity  of  blood  flowing  through 
it.  "If  an  increase  or  a  decrease  in  volume  were  an  infallible 
index  of  respective  changes  in  the  blood-flow,  then  obviously 
the  simultaneous  diminution  in  the  volume  of  the  internal  organs 
and  the  extremities  would  produce  a  condition  of  arterial  stag- 
nation. The  present  paper  presents  some  results  of  a  study  of 
the  blood-flow  through  other  parts  of  the  body  during  periods 

2  Dastre  and  Morat:  Arch,  de  Physiol.,  1882,  p.  337. 

'Bayliss  and  Bradford:  Journ.  Physiol,  1894,  xvi,  p.  10. 

■■  V.  Anrep:  Journ.  Physiol.,  1912,  xlv,  p.  307. 

^  Hallion  and  Francois-Franck :  Arch,  de  Physiol.,  viii,  p.  493. 

'  Cohnheim  and  Roy:  Arch.  f.  Pathol.  Anat.,  .xoii,  p.  424,  1882. 

'Roy:  Journ.  Physiol.,  1880-82,  iii,  p.  203. 

^  Bayliss:  Journ.  Physiol.,  1902,  xxviii,  p.  220  and  v.  Anrep;  loc.  cit.  p.  310. 


DISTRIBUTION   OF   BLOOD    ON   SPLANCHNIC    STIMULATION        17 

in  which  there  is  a  lessened  flow  through  the  portal  circuit.  I 
have  experimented  with  the  circuits  of  the  head  and  posterior 
extremity.  Measurements  of  the  blood-flow  were  taken  from 
the  carotid  artery,  jugular  vein,  femoral  artery,  and  femoral 
vein.  The  data  obtained  from  these  divisions  of  the  circulatory 
system  enable  us  to  determine  the  extent  of  compensation  for 
the  diminished  transfer  of  blood  through  the  portal  circuit. 

Method  of  investigation.  The  experiments  were  performed  upon 
dogs  weighing  6  to  12  kgm.  Narcosis  by  means  of  ether  was 
maintained  in  all  animals  throughout  the  experiments.  The 
general  blood-pressure  was  determined  in  the  left  femoral  artery 
by  means  of  a  mercury  manometer.  The  left  greater  splanchnic 
nerve  was  exposed  through  the  peritoneal  cavity,  isolated  for 
about  1  cm.  centrally  to  the  left  suprarenal  capsule,  ^nd  placed 
in  ■  shielded  electrodes.  In  some  experiments  the  nerve  was 
divided  and  in  others  it  was  left  intact,  but  in  the  two  cases  the 
general  character  of  the  results  did  not  differ  materially. 

At  the  outset  information  was  sought  regarding  circulatory 
conditions  by  registering  venous  pressures  in  different  parts  of 
the  body.  Such  determinations,  however,  serve  only  as  an  index 
of  qualitative  changes  in  the  volume  of  the  blood-flow  through 
a  part;  for  example,  an  increased  venous  pressure  is  indicative 
of  a  greater  flow,  and  decreased  pressure  an  indication  of  a  less- 
ened flow.  In  addition  I  have  made  quantitative  determina- 
tions of  the  blood-flow- in  the  circuits  of  the  head  and  posterior 
extremity  by  means  of  the  recording  stromuhr  described  by 
Burton-Opitz.'' 

The  determinations  of  venous  pressure  were  made  in  all  cases 
by  means  of  an  ordinary  manometer  filled  with  saline  solution 
and  connected  in  most  cases  with  the  blood-vessel  by  means 
of  a  T-canula.  The  readings  were  made  at  short  intervals  and 
inserted  directly  beneath  the  tracing  of  the  arterial  blood  pressure. 


Burton-Opitz :  Arch.  f.  d.  gesammte  Physiol.,  1908,  oxxi,  p.  150. 


18  D.   J.   EDWARDS 

OBSERVATIONS    OF    VENOUS    PRESSURE 

1 .  Femoral  vein.  Vasoconstriction  in  the  splanchnic  area  pro- 
duces a  gradual  increase  in  the  lateral  blood  pressure  in  this 
vein  which  attains  its  maximum  value  shortly  after  the  maxi- 
mum height  of  the  systemic  arterial  pressure  has  been  reached. 
It  is  followed  by  a  fall,  which  is  essentially  identical  in  character 
with  the  phase  of  increasing  pressure.  While  the  changes  in 
venous  pressure  pursue  a  course  that  is  practically  parallel  to 
that  of  the  arterial  pressure,  a  slight  difference  in  the  time  rela- 
tionship is  noticeable.  For  example,  an  average  of  a  series  of 
ten  readings  taken  after  stimuli  of  slightly  different  intensity 
and  duration,  shows  the  maximum  arterial  pressure  in  twenty- 
four  seconds  after  the  beginning  of  the  stimulation,  while  the 
corresponding  venous  readings  show  the  maximum  pressure  in 
thirty-three  seconds  after  the  beginning  of  the  stimulation. 

The  readings  of  arterial  pressure  in  this  set  of  experiments 
show  an  average  increase  of  25.2  mm.  Hg,  while  the  average 
venous  pressure  is  13  mm.  water  or  approximately  0.96  mm.  Hg. 
This  increase  in  venous  pressure  is  proportionally  large,  because 
the  average  normal  pressure  in  this  series  of  experiments  was 
4.9  mm.  Hg,  a  value  that  may  be  regarded  as  representing  a 
normal  pressure  since  it  is  only  0.5  mm.  Hg  less  than  the  aver- 
age pressure  obtained  by  Biu'ton-Opitzi"  in  eighteen  dogs  ranging 
in  weight  from  6  to  24  kgm. 

In  table  I  are  compiled  the  changes  in  pressure  in  the  femoral 
vein  upon  stimulation  of  the  splanchnic  nerve. 

In  view  of  the  work  of  v.  Anrep"  upon  the  relation  between 
the  changes  in  the  volume  of  the  posterior  extremity  and  the 
activity  of  the  adrenal  glands,  I  have  paid  especial  attention  to 
any  possible  change  in  venous  pressure  coincident  with  the 
second  phase  in  the  rise  of  arterial  blood-pressure.  I  have  been 
unable  to  observe  any  indication  of  an  alteration  in  the  blood- 
flow  at  this  period,  v.  Anrep  attributes  the  secondary  rise  in 
general  pressure  which  follows  stimulation  of  the  splanchnic,  to 

•»Burton-Opitz:  Amer.  Journ.  Physiol.,  1903,  ix,  p.  198. 
"v.  Anrep:  loc.  cit.  p.  310. 


DISTRIBUTION   OF   BLOOD    ON   SPLANCHNIC   STIMULATION        19 


TABLE  I 


EXPERIMENT 


NERVE  STIMULATED 


DURATION 
OF  STIMU- 
LATION IN 
SECONDS 


SECONDS 
AFTER 
BEGINNING 
OF  STIMU- 
LATION 


PRESSURE 

IN  FEMORAL 

ARTERY  IN 

MM.  Hg. 


PRESSURE 

IN  FEMORAL 

VEIN  IN 

filM.  HjO 


II 


III 


IV 


L.  splanchnic  nerve  undivided   27 


L.  splanchnic  nerve  undivided    40   ' 


L.  splanchnic  nerve  divided   i   53   < 


L.  splanchnic  nerve  undivided   46 


L.  splanchnic  nerve  divided   i   37 


6 
17 
27 
32 
41 
47 

9 

23 
34 
39 
51 

6 
11 
25 
37 
50 
102 
108 

16 
24 
32 
40 
58 
66 

11 

26 
■  36 
45 
64 
82 


74 

84 

90 

84 

76 

70 

70 

90 

74 

80 

72 

70 

68 

95 

114 

120 

146 

144 

132 

102 

98 

130 

166 

168 

160 

154 

134 

134 

66 

76 

88 

80 

72 

66 

66 


85 
90 
95 
100 
95 
90 
85 
80 
85 
95 
93 
90 
85 
65 
70 
80 
85 
80 
72 
70 
65 
60 
55 
55 
60 
55 
55 
50 
50 
55 
60 
64 
60 
55 
50 


20  D.   J.   EDWAKDS 

a  powerful  vasoconstriction  in  the  peripheral  blood  vessels  as 
a  result  of  an  increased  quantity  of  adrenalin  in  the  circulating 
blood  at  this  time.  In  support  of  this  view  he  has  shown  a 
decrease  in  the  volume  of  the  extremities.  If  the  diminished 
volume  of  the  posterior  extremities  were  accompanied  by  a 
marked  decrease  in  tlie  transfer  of  blood  within  the  limb,  we 
would  expect  to  obtain  a  drop  in  the  blood-pressure  in  the 
femoral  vein  following  closely  upon  the  second  phase  in  the 
arterial  blood-pressure  rise.  But  the  absence  of  such  a  drop  in 
pressure  should  not  be  interpreted,  I  believe,  as  opposed  to  the 
conclusions  of  v.  Anrep ;  on  the  contrary,  it  indicates  that  changes 
in  the  volume  of  the  posterior  extremity  cannot  be  relied  upon 
to  give  an  index  of  the  quantity  of  blood  flowing  through  it. 

2.  External  jugular  vein.  It  has  been  shown  by  Tschuewsky'^ 
that  the  blood  supply  of  the  head  is  about  four  times  greater 
than  that  of  the  posterior  extremity.  If  one  reasons  from  anal- 
ogy, it  is  evident  that  the  head  must  play  an  important  part 
in  compensating  for  the  diminished  transfer  of  blood  through 
the  portal  system.  The  external  jugular  vein  was  selected, 
because  it  is  the  principal  vessel  for  the  return  of  blood  from  the 
head. 

The  results  obtained  from  five  experiments  on  the  external 
jugular  vein  are  arranged  in  table  II. 

It  will  be  seen  that  there  is  a  marked  increase  in  pressure 
during  the  stimulation  of  the  splanchnic  nerve,  which  is  evident 
in  this  particular  set  of  experiments  as  an  average  rise  in  pres- 
sure of  1 .8  mm.  Hg.  If  contrasted  with  the  increase  in  femoral 
venous  pressure,  the  external  jugular  vein  shows  an  absolute  rise 
that  is  much  greater.  The  quantitative  variation  in  pressure 
indicated  in  this  table  is  characteristic  of  all  of  the  experiments 
upon  this  vein.  It  can  readily  be  observed  that  the  difference 
in  the  degree  of  increase  in  the  three  different  animals  from 
which  these  observations  were  taken  is  comparatively  small. 

The  rate  of  increase  in  pressure  in  the  external  jugular  vein 
as  compared  with  that  in  the  femoral  is  significant  in  showing 

'2  Tschuewsky :  Arch.  f.  d.  gesammte  Physiol.,  1903,  xcvii,  p.  386. 


TABLE  II 


EXPERIMENT 

NERVE  STimnLATED 

DURATION 
OF  STIMU- 
LATION IN 
SECONDS 

SECONDS 
AFTER 
BEGINNING 
OF  STIMU- 
LATION 

PRESSURE 

IN  FEMORAL 

ARTERY  IN 

MM.Hg 

PRESSURE 

IN  FEMORAL 

VEIN   IN 

MM.  H2O 

60 

20- 

7 

76 

15- 

12 

80 

10- 

14 

80 

5- 

I 

L.  splanchnic  nerve  undivided 

28      ' 

18 
23 

88 
90 

0 
5 

30 

82' 

0 

33 

76 

5-   . 

38 

64 

10- 

44 

60 
66 

15- 
20- 

5 

82 

15- 

9 

92 

10- 

12 

96 

5- 

II 

L.  splanchnic  nerve  undivided 

30      • 

1        14 
20 

98 
102 

0 

5 

33 

86 

0 

36 

78 

5- 

39 

72 

10- 

44 

68 
56 

20- 
5- 

4 

70 

0 

7 

72 

5 

III 

L.  splanchnic  nerve  undivided 

17      ■ 

12 
26 

72 
70 

10 
13 

30 

64 

10 

42 

58- 

5 

68 

60 
86 

0 
20- 

5 

104 

15- 

10 

120 

10- 

14 

120 

5- 

16 

120 

0 

IV 

L.  splanchnic  nerve  divided 

37      • 

19 
24 

118 
116 

5 
10 

30 

110 

12 

46 

100 

10 

,      53 

96 

5 

C2 

94 

0  ■ 

77 

98 
136 

5- 
30 

2 

140 

35 

6 

156 

45 

9 

162 

50 

V 

L.  splanchnic  nerve  undivided 

37 

12 

162 

55 

26 

152 

50 

35 

140 

45 

41 

136 

40 

64 

136 

30 

21 


22  .         D.    J.    EDWAEDS 

a  very  close  relationship  between  the  two.  For  example,  the 
time  required  for  a  5-mm.  increase  in  pressure  in  each  vein 
is  directly  proportional  to  the  total  increase  in  pressure  in 
each  vein.  It  is  evident,  therefore,  that  the  accelerated  flow 
through  the  limb  and  that  through  the  head  are  dependent  upon 
essentially  identical  haemodjmamic  factors.  Moreover,  the  com- 
paratively large  jugular  flow  might  well  be  expected  to  show 
any  temporary  fluctuations  in  pressure  that  would  result  from 
a  vasomotor  action  either  in  other  parts  of  the  body  exclusive 
of  the  splanchnic  area,  which  would  tend  to  shift  the  blood-stream, 
or  any  possible  vasomotor  changes  that  might  occur  in  the  head 
circuit.  The  uniform  character  of  the  records  during  the  entire 
phase  of  changed  pressure  makes  the  existence  of  such  secondary 
alterations  extremely  doubtful. 

The  absence  of  secondary  variations  in  the  blood-pressure,  and 
particularly  of  a  decrease,  is  taken  to  mean  that  the  circuit  of 
the  head  offers  at  no  time  an  effectual  hindrance  to  the  blood- 
flow  through  this  part.  Furthennore  the  degree  of  increase  in 
pressure  in  the  external  jugular  vein,  permits  of  rating  the  head 
circuit  as  a  most  important  factor  in  counterbalancing  the  dimin- 
ished transfer  of  blood  through  the  portal  system. 

In  some  experiments  venous  pressures  were  determined  in  the 
vicinity  of  the  right  auricle  by  inserting  a  catheter  through  the 
right  external  jugular  vein  into  the  superior  vena  cava.  The 
most  striking  feature  of  these  measurements  is  an  initial  rise 
in  pressure  amounting  to  only  from  5  to  10  mm.  of  water. 
Subsequently  the  pressure  returns  rapidly  to  nonnal,  and  may 
even  at  times  reach  a  value  very  slightly  below  the  normal  for 
a  short  period.  It  is  evident,  therefore,  that  the  change  in 
blood-pressure  close  to  the  heart  is  very  slight.  The  temporary 
increase  is  probably  due  to  a  squeezing  out  of  the  blood  from  the 
portal  vessels  from  vasoconstriction  in  the  splanchnic  area.  From 
these  considerations  it  appears  that  other  channels  have  equal- 
ized the  transfer  of  blood  so  that  the  pressure  close  to  the  heart, 
and  therefore,  the  volume  of  the  blood  returned,  is  affected  very 
little. 

3.  Pancreatic  and  renal  veins.  A  few  experiments  were  made 
upon  these  veins  to  obtain  information  regarding  the  pressure 


DISTRIBUTION    OF   BLOOD    ON   SPLANCHNIC    STIMULATION 


23 


conditions  in  them,  because  they  represent  venous  channels  in 
which  a  decrease  in  the  blood-flow  is  known  to  occur  during 
splanchnic  vasoconstriction.  The  results  were  somewhat  varied, 
showing  in  some  cases  fairly  regular,  in  others  fluctuating  changes. 

One  set  of  readings  (table  III)  will  illustrate  the  essential 
character  in  the  pancreatic  vein. 

It  will  be  noted  that  the  changes  in  venous  pressure  occur 
simultaneously  with  those  in  the  general  pressure,  but  in  an 
inverse  relation.  While  the  fall  in  pressure  was  not  always  so 
great  as  shown  in  this  set  of  readings,  an  initial  drop  was  ob- 
served in  every  case — a  result  the  opposite  of  that  obtained  with 
the  femoral  and  jugular  veins. 

Similarly  in  the  renal  vein  there  was  obtained  a  drop  in  pres- 
sure.    In  this  case,  however,  the  fall  was  usually  small  and  after 

TABLE  ni 

Left  divided  splanchnic  nerve  stimulated  for  twenty-three  seconds 


Seconds  after  beginning  of  stimu- 
lation                                      

86 
100 

11 

110 

95 

16 

118 

90 

21 

124 

80 

32 

116 

90 

36 
112 
100 

40 

Pressure  in  femoral  artery  in  mm. 
Hg                      

108 

Pressure  in  pancreatic  vein  in  mm. 
H-,0 

110 

this  initial  drop  of  a  few  millimeters  there  was  in  many  cases  a 
partial  return  to  the  normal  before  the  rise  in  general  pressure 
reached  a  maximum.  It  is  evident  from  readings  taken  from 
the  central  end  of  the  renal  vein,  and  from  a  catheter  inserted 
into  the  inferior  vena  cava,  that  the  pressure  does  not  change 
markedly  in  the  latter  vessel  during  vasoconstriction  in  the 
splanchnic  area.  The  pressures  in  the  renal  vein  were  of  neces- 
sity measured  close  to  the  vena  cava,  therefore  the  small  drop 
in  renal  pressure  was  due,  I  believe,  to  the  equalizing  tendency 
of  the  nearly  uniform  pressure  in  the  large  vena  cava. 

The  experiments  upon  the  pancreatic  and  renal  veins  show  an 
unmistakable  drop  in  pressure.  The  fall  is  in  many  cases  small 
but  the  principal  significance  lies  in  the  fact  that  it  shows  a  direct 
relationship  between  the  changes  in  venous  blood-pressure  and 
the  volume  of  the  blood-flow. 


24  D.    J.    EDWARDS 

MEASUREMENTS    OF   THE   BLOOD-FLOW 

1.  Flow  through  the  head.  The  experiments  upon  the  blood- 
pressure  in  the  external  jugular  vein  gave  results  that  indicate 
an  increased  flow  through  the  head  during  stimulation  of  the 
splanchnic  nerve.  The  method,  however,  was  not  applicable  to 
quantitative  determinations.  The  experiments  now  to  be  de- 
scribed were  undertaken  with  this  end  in  view.  It  was  also 
hoped  that  the  data  obtained  would  give  information  regarding 
the  proportional  amount  of  compensation  for  the  diminished 
portal  flow  which  is  afforded  by  the  head  circuit. 

The  blood-flow  in  the  external  jugular  vein  was  taken  as  the 
index  of  flow  through  the  head,  because  it  is  the  principal  vessel 
for  the  return  of  the  blood  from  this  part.  In  the  results  of 
these  experiments  three  things  are  obvious — first,  vasoconstric- 
tion in  the  splanchnic  area  produces  a  marked  increase  in  the 
blood-flow  through  the  head;  second,  the  changes  in  the  flow 
occur  in  the  same  general  manner  as  the  changes  in  blood- 
pressure  within  the  vein;  and  third,  there  is  no  evident  diminu- 
tion in  the  flow  coincident  with  the  second  phase  in  the  increase 
in  arterial  blood  pressure. 

It  will  be  seen  from  table  IV  that  the  average  blood-flow 
prior  to  the  stimulation  of  the  splanchnic  nerve  was  about  1.99 
cc.  in  a  second  and  the  average  systemic  blood  pressure  corre- 
sponding to  this  blood-flow  was  0.89  mm.  Hg.  In  terms  of  a 
systemic  pressure  of  100  mm.  Hg,  this  would  give  a  flow  of 
2.23  cc.  per  second,  a  value  that  is  close  to  the  average  noraial 
of  2.4  cc.  per  second  obtained  by  Burton-Opitz.^'  Stimulation 
of  the  splanchnic  nerve  with  current  of  moderate  strength  for 
an  average  period  of  forty-four  seconds  gave  an  increase  of  about 
12.5  per  cent  in  the  amount  of  blood-flow  through  this  vein. 

In  table  IV  are  arranged  the  results  of  five  experiments  upon 
the  flow  in  the  jugular  vein. 

Let  us  turn  for  a  moment  to  the  proportional  compensatory 
action  afforded  by  this  circuit.  If  we  take  the  average  normal 
flow  in  the  external  jugular  as  144  cc.  per  minute,  2.4  cc.  per 

''  Burton-Opitz :  Amer.  Journ.  Physiol.,  1902,  vii,  p.  435. 


DISTRIBUTION   OF   BLOOD   ON   SPLANCHNIC   STIMULATION        25 


TABLE  IV 
Experiment  1 


PHASE 

OF  STBO- 

MTJHR 

DURATION 
OF  PHASE 

QUANTITY 
OF  BLOOD 
PER  PHASE 

QUANTITY 

OF  BLOOD 

PER  SECOND 

PRESSURE 

IN  FEMORAL 

ARTERY  IN 

MM.  Hg. 

CONDITIONS 

seconds 

CC. 

CC. 

1 

2 
3 

10.2 
13.6 
12.0 

21.75 
21.75 
21.5 

2.13 
1.60 
1.79 

82 
82 
82 

Before     stimulation     of    left 
splanchnic  nerve 

4 

12.4 

21.75 

1.75 

95 

5 

9.8 

21.75 

2.22 

104 

6 

10.4 

21.50 

2.06 

106 

During  stimulation 

7 

9.5 

21.75 

2.28 

106 

8 

11.0 

21.75 

1 .97 

106 

9 

10.5 

22.5 

2.14 

100 

10 
11 

•  12.2 
12.8 

22.5 
21.75 

1.84 
1.62 

94 
90 

>  After  stimulation 

12 

14.0 

21.2 

1.51 

88 

Experiment ; 


1 

2 
3 

9.2 

10.4 

9.8 

21.0 

19.7 

.20.0 

2.28 
1.89 
2.05 

70 
70 

72 

Before    stimulation    o 
splanchnic  nerve 

f     left 

4 

10.0 

20.5 

2.05 

80 

5 

8.2 

21.5 

2.62 

84 

6 

7 

9.0 

7.6 

20.7 
21.5 

2.30 
2.83 

90 
94 

'  During  stimulation 

8 

'8.8 

21.7 

2.41 

96 

9 

6.2 

20.2 

3.25 

98 

10 

8.5 

19.5 

2.29 

94 

- 

11 

7.5 

20.7 

2.76 

90 

■  After  stimulation 

12 

10.8 

22.0 

2.10 

86 

Experiment  3 


1 

12.4 

20.75 

1.67 

84 

1  Before    stimulation    o 

f    left 

2 

20.0 

21.2 

1.06 

84 

/      splanchnic  nerve 

3 

13.6 

21.2 

1.56 

98 

4 

17.0 

21.75 

1.28 

106 

■  During  stimulation 

5 

11.2 

21.5 

1.92 

106 

6 

7 

16.5 
15.0 

21.0 
20.75 

1.27 
1.38 

104 
98 

>  After  stimulation 

26 


D.   J.   EDWARDS 


TABLE  IV— Continued 

Experiment  4 


PHASE 

OF  STRO- 

MUHH 

DURATION 
OP  PHASE 

QUANTITY 
OF  BLOOD 
PER  PHASE 

QUANTITY 

OF  BLOOD 

PER  SECOND 

PRESSURE 
'II.^Z7^                                      CONDITIONS 
MM.  Hg. 

seconds 

CC. 

CC. 

1 

11.8 

22.2 

1.96 

76 

^  Before    stimulation    o 

f    left 

2 

15.6 

21.2 

1.36 

76 

splanchnic  nerve 

3 

11.5 

21,0 

1.73 

76 

4 
5 

14.0 
9,5 

21.75 
22.5 

1.55 
2.36 

94 
98 

•  During  stimulation 

6 

13.8 

22.0 

1.59 

100 

7 
8 

9.3 
16.0 

21.2 
21.5 

2.27 
1.33 

100     ! 

88     \ 

>  After  stimulation 

Experiment  5 


1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 


8.4 

20.0 

2.38 

136       1 

5.2 

19.7 

3.78 

136 

6.8 

19.7 

2.89 

136      1 

5.5 

19.2 

3.48 

136 

7.5 

18.7 

2.49 

136 

5.0 

18.7 

3.74 

144       1 

6.8 

19.2 

2.82 

154 

5.2 

19.7 

3.78 

160        [ 

8.4 

19.5 

2.32 

144 

5.5 

19.5 

3.54 

122 

8.5 

19.2 

2.25 

120       1 

7.5 

18.7 

2.65 

130      ••] 

Before     stimulation     of     left 
splanchnic  nerve 


During  stimulation 


After  stimulation 


second,  then  during  the  period  of  stimulation  of  the  splanchnic 
nerve  there  is  an  increase  of  approximately  17  cc.  in  a  minute. 
The  compensation  offered  by  the  head  circuit  as  figured  on  this 
basis  would  amount  to  34  cc.  in  a  minute  for  the  two  external 
jugular  veins.  This  value,  however,  would  probably  not  repre- 
sent the  total  compensation  afforded  by  the  head  portion  of  the 
circulatory  system,  because  the  internal  jugulars  may  be  expected 
to  take  a  part  proportional  to  their  normal  volume  of  flow. 
Bearing  in  mind  now  the  fact  stated  in  the  early  part  of  this 
paper  that  splanchnic  vasoconstriction  may  produce  a  dimin- 
ished transfer  of  blood  through  the  portal  circuit,  to  the  extent 


DISTRIBUTION    OF   BLOOD    ON    SPLANCHNIC    STIMULATION        27 

of  about  68  cc.  in  a  minute,  it  is  obvious  that  the  head  circuit 
alone  is  capable  of  compensating  for  more  than  one-half  of  this 
quantity. 

The  average  flow  in  these  experiments  during  stimulation  of 
the  splanchnic  nerve  was  2.26  cc.  per  second,  and  the  average 
systemic  pressure  for  the  same  period,  obtained  by  taking  the 
mean  pressure  for  each  phase  of  the  stromuhr,  was  107  mm.  Hg. 
These  values  give  a  volume  of  flow  per  100  mm.  Hg  pressure,  of 
2.11  cc.  per  second.  If  we  now  compare  this  with  the  normal 
flow  of  2.23  cc.  per  second,  obtained  in  these  experiments,  it  is 
evident  that  there  is  a  greater  volume  of  flow  per  second  with 


Fig.  1     Record  OF  THE  AccelerjVted  Blood-Flow  IN  THE  External  Jugular 
Vein  During  Stimulation  of  the  L.  Splanchnic  Nerve 

1,  Time  in  seconds;  3,  blood-pressure  in  femoral  artery  (mercury  manometer) ; 
3,  stromuhr;  4,  blood-pressure  in  jugular  vein  (membrane  manometer)  5,  zero 
blood  pressure;  8  to  7,  period  of  stimulation. 


the  high  systemic  blood-pressure,  yet  in  proportion  to  the  head 
of  pressure  there  is  a  diminished  efficiency.  The  increase  in 
the  flow  bears  a  close  relation  to  the  corresponding  changes  in 
blood-pressure,  as  is  illustrated  in  figure  1.  There  is  first  a 
short  latent  period  which  is  followed  by  a  gradually  increasing 
flow.  The  maximum  flow  is  usually  attained  at  about  the  time 
of  highest  systemic  blood-pressure.  If  the  period  of  stimula- 
tion is  short,  e.g.,  ten  to  fifteen  seconds,  the  maximum  flow  does 
not  appear  until  after  the  cessation  of  the  stimulation. 


28  D.    J.    EDWARDS 

The  graphic  tracing  of  the  blood-flow,  with  respect  to  the  two 
phases  in  the  increase  of  systemic  blood-pressure,  shows  no 
indication  of  a  variation  that  could  be  associated  with  a  vaso- 
motor activity  in  the  carotid  circuit.  The  first  phase  in  the 
rise  of  blood-pressure  is  so  short  that  it  is  questionable  whether 
its  effect  could  be  demonstrated  with  the  stromuhr,  but  in  case 
of  the  second  phase,  there  is  obviously  no  marked  change  in  the 
volume  of  blood-flow.  If  the  diminished  volume  of  the  extrem- 
ities, said  to  occur  at  this  time,  were  accompanied  by  a  pro- 
nounced decrease  in  the  blood-flow  in  these  parts;  then  secondary 
alterations  in  the  already  accelerated  blood  flow  through  the 
head  circuit  might  be  expected  to  occur.  The  fact  that  no  such 
secondary  changes  in  the  flow  have  been  recorded  in  these  experi- 
ments, if  taken  together  with  the  results  obtained  upon  the 
femoral  vein  which  are  to  follow,  support  the  view  that  the 
volume  decrease  of  the  limb  is  insufficient  to  cause  a  marked 
change  in  the  blood-flow  through  these  parts. 

2.  Flow  through  the  posterior  extremity.  This  series  of  experi- 
ments was  made  upon  the  femoral  vein  and  femoral  artery.  In 
brief  the  results  show  an  increased  flow  through  this  part  during 
splanchnic  stimulation,  and  no  retardation  coincident  with  the 
second  rise  in  general  blood-pressure.  The  total  compensation 
through  this  circuit  is  much  smaller  than  that  afforded  by  the 
head  circuit,  because  the  total  blood-flow  is  relatively  small. 

Femoral  vein.  The  average  obtained  from  five  experiments 
upon  the  flow  in  this  vein  shows  an  increase  of  a  fraction  less 
than  15  per  cent  with  an  initial  mean  systemic  pressure  of  91 
mm.  Hg,  a  period  of  stimulation  of  thirty-three  seconds,  and  a 
mean  systemic  pressure  during  this  period  of  130  mm.  Hg.  The 
graphic  record  of  this  increase  in  blood-flow  is  very  similar  in 
character  to  the  record  of  the  same  phenomenon  in  the  jugular 
vein.  Likewise  there  is  shown  in  the  actual  percentage  increase 
in  the  blood-flow  in  the  two  cases  a  difference  of  about  2.5  per 
cent  which  is  well  within  the  limit  of  experimental  error. 

The  average  normal  blood-flow  in  the  femoral  has  been  deter- 
mined" as  0.85  cc.  per  second     This  value  taken  with  the  per- 

"  Burton-Opitz:  Amer.  Journ.  Physiol.,  1903,  ix,  p.  161. 


DISTRIBUTION   OF  BLOOD    ON   SPLANCHNIC   STIMULATION        29 

centage  of  increase  obtained  in  this  set  of  experiments  permit 
of  quantitative  data  upon  the  compensatory  flow  through  the 
posterior  extremities.  Each  extremity  upon  this  basis  would 
afford  a  compensation  of  about  7.6  cc.  per  minute  or  15.2  cc. 
per  minute  for  the  two  posterior  extremities.  If  we  assume 
that  the  circulation  of  the  anterior  extremity  gives  an  increase 
of  blood  flow,  during  stimulation  of  the  splanchnic  nerve,  approx- 
imately the  same  as  obtained  from  the  posterior  extremity,  the 
total  quantity  of  blood  prevented  from  returning  to  the  venous 
side  by  way  of  the  portal  vein  (see  p.  15)  during  vasoconstric- 
tion in  the  splanchnic  area,  is  practically  all  compensated  for 
by  the  circulations  of  the  head  and  extremities. 

In  table  V  are  compiled  data  from  four  experiments  to  show 
the  increase  in  flow  in  the  femoral  vein  during  the  period  of 
stimulation  of  the  splanchnic  nerve. 

A  final  feature  evident  from  the  records  of  the  experiments 
now  under  discussion  is  a  lack  of  correlation  between  the  rate 
of  the  blood-flow  through  the  limb  and  the  changes,  said  to  occur, 
in  its  volume.  It  has  been  demonstrated"^^  that  the  second 
phase  in  the  general  rise  of  blood-pressure  resulting  from  stimu- 
lation of  the  splanchnic  nerve  is  accompanied  by  a  diminished 
volume  of  the  limb,  and  such  changes  have  been  associated  with 
a  diminished  blood-flow.  But  in  my  experiments  the  blood-flow 
was  not  diminished  at  this  phase  in  the  blood-pressure  rise;  on 
the  contrary  the  flow  was  always  accelerated  during  the  entire 
phase  of  raised  systemic  blood-pressure,  and  in  many  cases  the 
maximum  flow  was  recorded  towards  the  end  of  or  immediately 
following  the  second  phase  in  the  blood-pressure  increase.  This 
fact  has  a  greater  significance  when  the  total  blood  exchange  is 
considered.  A  diminished  volume  of  some  of  the  abdominal 
organs  has  already  been  referred  to  on  page  16,  and  moreover  it 
has  been  shown'*^  that  in  these  organs  there  is  a  decrease  in  blood- 
flow  following  stimulation  of  the  splanchnic  nerve.  If  the  vol- 
ume of  the  limb  were  likewise  accompanied  by  a  significant 
diminution  in  the  blood-flow  through  it,  then  the  circulation  of 

•5  V.  Anrep:  loc.  cit.  p.  307. 
1' Burton-Opitz :  loc.  cit. 


30 


T>.    J.    EDWARDS 


TABLE  V 


Experiment  1 


PHASE 

OF 
STRO- 
MUHB 

DURATION 

OF 

PHASE 

QTJ  A.NTITY 

OF  BLOOD 

PER 

PHASE 

QUANTITY 

OF  BLOOD 

PER 

SECOND 

PRESSURE 

IN 
FEMORAL 
ARTERY     , 

CONDITIOMS 

seconds 

CC. 

CC. 

mm. 

1 

22.0 

18.7 

0.85 

114 

1  Before     stimulation     of    left 

2 

23.0 

18.5 

0.80 

114 

/      splanchnic  nerve 

3 

17.0 

17.2 

1.0 

124 

4 
5 

12.5 
11.0 

17.5 
19.5 

1.40 
1.70 

124 
110 

•  During  stimulation 

6 

15.0 

19.5 

1.30 

108 

7 

17.0 

8.7 

1.10 

106 

After  stimulation 

Experiment  2 

1 

25.0 

18.0 

0.72 

/Before     stimulation     ol 
\      splanchnic  nerve 

left 

2 

21.5 

18.0 

0.86 

122 

126         ■  During  stimulation 

118 

3 

16.6 

19.0 

1.14 

4 

14.5 

19.2 

1.32 

5 
6 

19.3 
24.2 

19.72 
17.2 

1.00 
0.71 

112       1 

:  r  After  stimulation 
112       [J 

Experiment .? 


1 

38.0 

15.5 

0.40 

90 

1  Before     stimulation     of     left 

2 

12.0 

5.5 

0.46 

94 

J      splanchnic  nerve 

. 

3 

4 

19.0 
22.0 

11.0 

18.0 

0.60 

0.82 

108 

104 

r  During  stimulation 

5 

25.0 

18.5 

0.74 

1 

118 

After  stimulation 

Experiment  4 


1 

22.8 

21.0 

0.91 

84 

1  Before     stimulation     o 

left 

2 

17.2 

20.7 

1.20 

84 

/      splanchnic  nerve 

3 

18.2 

22.2 

1.22 

86 

4 

9.3 

23.0 

2.5 

106 

During  stimulation 

5 

11.8 

22.2 

1.88 

104 

6 

10.0 

21.5 

2.15 

94 

7 

13.2 

21.2 

1.60 

90 

8 
9 

12.0 
14.2 

22.0 
21.5 

1.66 
1.51 

90 
90 

•  After  stimulation 

10 

13.2 

20.5 

1.55 

90 

DISTRIBUTION    OF   BLOOD    ON   SPLANCHNIC    STIMULATION        31 

the  extremities  would  antagonize  the  circulation  of  the  splanch- 
nic area  and  there  would  result  a  greatly  lessened  transfer  of 
blood  to  the  venous  side.  The  pressure  conditions  in  different 
parts  of  the  venous  system,  as  set  forth  in  the  first  part  of  this 
paper,  indicate  that  the  venous  return  is  not  materially  lessened 
during  splanchnic  vasoconstriction. 

The  absolute  decrease  in  the  volume  of  the  limb  is  not  evident 
in  the  studies"  upon  this  subject.  But  from  the  method  em- 
ployed in  registering  this  change,  and  the  solid  character  of  the 
organ  itself,  it  seems  probable  that  the  change  is  very  small. 
From  these  considerations  the  conclusion  seems  warranted  that 
the  diminution  in  the  volume  of  the  limb  is  not  sufficient  to 
affect  appreciably  its  blood-flow. 

Femoral  artery.  A  few  experiments  were  made  upon  the  blood- 
flow  in  this  artery  to  detei-mine  whether  the  inflow  to  the  pos- 
terior extremity  corresponds,  at  all  closely,  to  the  outflow;  since 
the  possibility  exists  that  a  part  of  the  accelerated  outflow  may 
be  due  to  a  squeezing  out  of  the  contained  blood  from  vaso- 
constriction in  this  organ.  The  records  show  an  increase  in  the 
arterial  blood-flow,  which  is  essentially  identical  in  character 
with  that  obtained  from  the  femoral  vein.  An  average  of  three 
experiments  shows  an  increase  of  16.8  per  cent,  a  value  that  is 
likewise  very  close  to  similar  detenninations  upon  the  femoral 
vein.  In  fact  this  uniformity  in  the  general  character  of  the 
records,  and  the  close  agreement  in  the  percentage  increase  in 
the  blood-flow,  are  the  most  significant  features  of  the  results. 
These  observations  make  it  probable  that  the  accelerated  flow 
in  the  femoral  vein  is  independent  of  mechanical  factors  within 
the  limb. 

3.  Flow  through  a  denervated  kidney.  In  this  series  of  experi- 
ments the  left  kidney  was  used  in  all  cases.  It  was  isolated  from 
nervous  influences  by  dividing  all  the  nerve  fibers  leading  to  it. 
The  blood-flow  through  such  an  organ  might  be  expected,  a 
priori,  to  follow  the  changes  in  general  blood-pressure.  I  pro- 
ceeded to  investigate  this  by  first  making  use  of  the  oncometric 


"  Bayliss:  loc.  cit.  p.  222;  v.  Anrep:  loc.  cit.  p.  310. 


32 


D.   J.    EDWARDS 


method  to  record  the  changes  in  the  volume  during  stimulation 
of  the  splanchnic  nerve.  In  this  feature  my  results  agree  essen- 
tially with  those  of  v.  Anrep.  Figure  2  shows  a  graphic  record 
of  a  typical  experiment  of  this  kind.  Here  the  rapid  increase 
in  volume  during  the  initial  rise  in  systemic  pressure  is  attributed 
to  a  passive  dilatation  of  the  blood-vessels  produced  by  the  in- 
creased systemic  blood-pressure.  The  sudden  decrease  in  the 
volume  coincident  with  the  second  phase  in  the  rise  of  general 
blood-pressure  is  attributed  to  the  augmented  secretion  of  ad- 


m^mm^ 

1 

-*" 

^^^^^1 

A'V^^^^^^^A(^A/vwM^www^AA^'^ 

fVV\fiANW\ 

fViAAfWWifWWWW 

"^•^x 

^^.^f#^^N^ 

f{^ 

•PP 

•         -/ 

^^ 

V 

1 

n^N\jYf\[\(\i\|\(\fi^Y^r,j\j>^^ 

«P>^- 

\A!V\MV.xr,-r 

hJXj\rVr\*vA.  r*  A 

1 

Fig.  2    Record  of  the  Changes  in  the  Volume  of  a  Denebvated  Kidney 
During  Stimulation  of  the  L.  Splanchnic  Nerve 

/,  Time  in  seconds;  2,  blood-pressure  in  femoral  artery  (mercury  manometer); 
S,  volume  of  the  kidney  (oncometer);  4,  zero  of  blood  pressure;  S  to  6,  period 
of  stimulation;  7,  interval  of  40  seconds. 


renalin  from  stimulation  of  the  splanchnic  nerve.  This  phase, 
namely,  the  decrease  in  the  volume,  I  have  been  able  practically 
to  abolish  by  using  a  short  series  of  stimulations.  Each  stimu- 
lation was  maintained  for  a  period  of  about  twenty  seconds,  and 
repeated  four  to  six  times  at  intervals  of  about  fifty  seconds. 
In  this  case  the  supply  of  adrenalin  had  evidently  become  ex- 


DISTRIBUTION   OF   BLOOD    ON   SPLANCHNIC   STIMULATION        33 

hausted,  because  the  splanchnic  vasomotor  mechanism  was  still 
capable  of  producing  the  initial  rise  in  general  pressure  but  the 
secondary  rise  was  not  shown. 

In  order  to  determine  whether  there  is  a  correlation  between 
these  changes  in  volume  of  the  kidney  and  the  quantity  of  blood 
traversing  it,  I  made  records  of  the  blood-flow  by  inserting  the 
stromuhr  into  the  renal  vein.  The  results  show  a  moderate 
increase  in  flow  during  practically  one  phase  of  the  record  of  the 
stromuhr.  This  increase  follows  very  closely  upon  the  applica- 
tion of  the  stimulation  to  the  splanchnic  nerve,  and  its  duration 
is  apparently  identical  with  the  increase  in  the  volume  described 
above.  Subsequently  there  is  a  marked  diminution  in  the  flow, 
which  continues  during  the  remainder  of  the  stimulation  period 
and  for  a  time  thereafter.  In  fact  this  retarded,  yet  gradual, 
return  to  the  normal  flow  is  one  of  the  striking  features  of  the 
experiment.  The  decrease  in  flow  occurs  simultaneously  with  the 
second  phase  in  the  rise  in  systemic  blood-pressure.  In  this 
feature  it  coincides,  therefore,  with  the  decrease  in  the  volume 
of  this  organ  described  by  v.  Anrep  and  corroborated  by  experi- 
ments given  in  this  paper.  It  can  hence  be  accepted  without 
question  that  this  diminished  blood-flow  is  produced  by  the 
action  upon  the  renal  blood  vessels  of  the  adrenalin,  which  is 
present  in  the  circulating  blood  in  larger  quantities  at  this  time. 

The  observations  described  above  make  it,  I  think,  clear  that 
the  rate  of  the  blood-flow  through  a  denervated  kidney  does  not 
passively  follow  the  rise  in  general  blood  pressure,  as  it  might 
at  first  thought  be  expected  to  do.  In  this  feature  my  records 
differ  slightly  from  those  obtained  by  Burton-Opitz'^  but  this 
discrepancy  is  more  apparent  than  real  since  it  has  been  shown 
that  the  decrease  in  flow  occurs  during  longer  periods  of  time 
than  were  used  in  the  experiments  of  Burton-Opitz.  Further 
it  is  to  be  noticed  that  there  is  an  unquestionable  relationship 
between  the  relative  volume  of  this  organ,  and  the  quantity  of 
blood  flowing  through  it  at  any  given  time  during  the  period  of 
splanchnic  stimulation.     This  is  no  contradiction  to  the  conclu- 

"  Burton-Opitz:  Arch.  f.  d.  gesammte  Physiol.,  1909,  cxxvii,  p.  143. 


34  D.   J.   EDWARDS 

sion  reached  on  page  32  regarding  the  change  in  the  volume  of 
the  posterior  extremity  and  its  blood-flow.  The  two  cases  are 
essentially  different,  in  that  the  kidney  presents  a  small,  flaccid, 
and  highly  vascular  organ,  in  which  the  absolute  changes  in 
volume  are  proportionally  large;  while  the  limb  is  large  its  tissue 
is  much  firmer  in  character,  and  from  the  evidence  obtainable 
it  appears  that  the  absolute  changes  in  volume  are  proportionally 
small.  For  these  reasons  it  seems  probable,  that  the  total  vas- 
cular area  of  the  limb  would  be  insufficiently  affected  by  the 
diminution  in  volume,  from  the  increased  adrenalin  in  the  blood, 
to  produce  a  retarding  action  upon  the  blood-flow  through  it. 

The  facts  here  reported  seem  to  emphasize  the  necessity  of 
using  caution  in  drawing  conclusions  regarding  the  blood-flow 
through  an  organ  from  determinations  of  its  changes  in  volume. 

SUMMARY 

Stimulation  of  the  splanchnic  nerve  produces  changes  in  the 
distribution  of  the  blood  that  permit  of  the  following  conclusions : 

1.  The  blood-pressure  in  the  femoral  vein  shows  an  average 
increase  of  0.96  mm.  Hg  from  stimulation  for  forty  seconds.  The 
phases  of  increase  and  final  return  to  normal  closely  agree  with 
similar  changes  in  the  general  pressure. 

2.  An  average  increase  of  1.8  mm.  Hg  was  obtained  in  the 
external  jugular  vein  by  stimulation  for  thirty  seconds. 

3.  In  the  pancreatic  and  renal  veins  a  fall  in  pressure  results, 
which  is  usually  small  and  variable  in  character.  A  few  deter- 
minations in  the  inferior  and  superior  vena  cava  indicate  slight 
changes  in  the  pressure. 

4.  The  measurements  of  the  blood-flow  in  the  external  jugular 
vein  show  an  increase  of  12.5  per  cent.  Estimated  from  the 
normal  flow  this  gives  for  the  two  jugular  veins  a  compensatory 
flow  of  34.4  cc.  per  minute. 

5.  The  blood-flow  in  the  femoral  vein  showed  an  increase  of 
15  per  cent.  The  estimated  compensatory  flow  in  this  case  gave 
a  value  for  the  two  posterior  extremities  of  15.3  cc.  per  minute. 


DISTRIBUTION   OF   BLOOD   ON   SPLANCHNIC    STIMULATION       35 

6.  If  we  assume  that  the  circulation  of  the  anterior  extremities 
affords  an  accelerated  flow  approximately  equal  to  that  of  the 
posterior  extremities,  then  the  increased  transfer  of  blood  per- 
mitted by  the  vascular  circuits  of  the  head  and  extremities 
together  is  sufficient  to  compensate  for  the  diminished  flow 
through  the  portal  circuit. 

7.  There  is  no  indication  in  either  the  readings  of  venous  pres- 
sure or  the  stromuhr  records  from  the  jugular  and  femoral  veins 
of  a  change  in  flow  coincident  with  the  second  phase  in  the  rise 
of  the  general  blood-pressure. 

8.  The  denervated  kidney  showed  a  correlation  between  its 
relative  volume  and  the  quantity  of  blood  flowing  through  it. 
There  was  a  temporary  increase  in  flow  coincident  with  the 
initial  increase  in  volume,  and  a  marked  decrease  in  the  flow 
corresponding  to  the  similar  change  in  the  volume. 

9.  A  change  in  the  volume  of  an  organ  is  not  an  infallible 
criterion  of  the  relative  quantity  of  blood  flowing  through  it. 

I  wish  to  express  my  sincerest  thanks  to  Prof.  Frederic  S.  Lee 
for  his  kind  advice  and  criticism.  I  have  much  pleasure  also  in 
thanking  Prof.  R.  Burton-Opitz  for  suggesting  the  problem  and 
for  invaluable  help  he  has  given  me  throughout  the  work. 


VITA 

I  was  born  on  September  7th,  1882,  in  Oxford,  Maine,  and  was 
graduated  from  Hebron  Academy  with  the  class  of  1902.  I  entered 
the  University  of  Maine  in  the  same  year  and  received  the  degree  of 
Bachelor  of  Science  in  1906.  In  the  summer  season  of  1905  I  com- 
pleted the  course  in  Invertebrate  Zoology,  and  in  1906  the  course  in 
Embryology,  at  the  Marine  Biological  Laboratories,  Woods  Hole, 
Massachusetts. 

I  entered  upon  my  duties  as  assistant  in  biology  at  the  Univer- 
sity of  Maine  in  1906,  was  advanced  to  instructor  in  1907,  and  was 
appointed  assistant  entomologist  in  the  Maine  Agricultural  Experi- 
ment Station  in  June,  1908.  I  resigned  this  position  in  the  autumn 
to  accept  an  assistantship  in  zoology  in  Columbia  University  for 
1908-09,  and  in  the  summers  of  1909  and  1910,  I  received  appoint- 
ment to  the  same  position  for  the  Summer  School  session.  In  the 
autumn  of  1909  I  was  appointed  tutor  in  the  College  of  the  City  of 
New  York,  and  have  now  been  advanced  to  instructor  for  1914-15. 

I  have  spent  several  summers  at  the  research  laboratories  of  the 
Marine  Biological  Association,  and  the  United  States  Bureau  of 
Fisheries,  at  Woods  Hole,  Massachusetts.  During  a  part  of  this 
time  I  studied  the  anatomy  and  the  vasomotor  phenomena  of  the 
sympathetic  nervous  system  in  the  turtle,  and  the  results  of  this 
were  published  in  the  American  Journal  of  Physiology,  volume 
thirty-three,  1914. 

August  20th,  1914  (Sigeed)  DAYTON    JAMES    EDWARDS 


